Protein is an important and required component of a balanced diet for all animals. Traditionally, milk or milk products have been used to supply young animals with protein. However, because milk products are fairly expensive, it is often difficult to include milk products in the diet of all young animals. Moreover, some animals cannot tolerate milk products that have been derived from milk from a different species of animal. Accordingly, attempts have been made to identify other, less expensive sources of protein to replace, in whole or part, the milk protein used in the diet of young animals.
Due to its low cost and availability, the soybean, primarily in the form of soy flour, has been used as a protein source in the diet of many species of young animals. Unfortunately, some species of animals, including preruminant calves, human infants, and pigs typically develop allergies to soybean products. Such allergic animals exhibit high concentrations of circulatory IgG antibodies to glycin and .beta.-conglycinin, the two major storage proteins of soybeans. Ingestion of conventional soy flour by allergic calves typically produces digestive abnormalities including changes in the rate of movement of digesta in the abomasum and small intestine, increased gut permeability to protein macromolecules, and inflammation of the intestinal mucosa. This allergic reaction is manifested by loss of appetite, poor growth, low weight gain and diarrhea.
Efforts have been made to develop processes which remove or inactivate the allergenic components in soy products. One such process involves extracting soy flour with alcohol and water. Unfortunately this process is expensive and removes a substantial portion of the valuable carbohydrate component of the soy flour. In addition, the resulting products, which are known as soy concentrates, do not suspend well in water.
Another process involves separating the soy flour protein into multiple protein fractions. Unfortunately, this fractionation process is expensive and removes most of the carbohydrates from the resulting products, which are known as "isolates." Moreover, the isolates may still contain antigenic proteins.
Accordingly, it is desirable to have a new process which reduces the undesirable characteristics of soy flour. A process that does not remove the nutritionally valuable components from soy flour would be especially desirable. It is also desirable to have a new modified soy flour feed that does not induce diarrhea, poor growth or weight loss in the recipient animal and that is relatively inexpensive to produce.